Shell is waterproof 210T Polyester, the liner is hollow cotton fiber filling is super soft and warm. Hood with drawstrings circle your head and keep warm.The draft tubes circle you round to keep cold out. This 4 season ultra light hammock compatible sleeping bag integrates with any hammock to serve as both an underquilt and a top quilt. Thicken:Comfort Limit is 32-68 Degrees F;Thin:Comfort Limit is 41-77 Degrees F. Professionally designed for hammocking while through - hiking, backpacking, camping.this bag boasts superior weight-to-warmth ratio and is the ultimate hammock compatible sleeping bag for saving space and weight. Specification: Mummy Sleeping Bags Size:230x84x55cm/90.55x33.07x21.65inch Thicken Weight:2050g Thin Weight:1520g Package Includes: 1 x sleeping bag with a carry bag(not include hammock)